WebChart.java package net.sentom.chart;
import java.awt.Insets;
import java.awt.Font;
import java.io.PrintWriter;
import javax.servlet.http.HttpSession;
import org.jfree.data.*;
import org.jfree.chart.*;
import org.jfree.chart.plot.*;
import org.jfree.chart.entity.*;
import org.jfree.chart.urls.*;
import org.jfree.chart.servlet.*;
import org.jfree.chart.labels.StandardPieToolTipGenerator;
/**
* @author sentom
*
* To change the template for this generated type comment go to
* Window>Preferences>Java>Code Generation>Code and Comments
*/
public class WebChart {
private DefaultPieDataset data = new DefaultPieDataset();
public void setValue(String key,double value){
data.setValue(key,value);
}
public String generatePieChart(String title, HttpSession session, PrintWriter pw) {
String filename = null;
try {
//建立chart對象
PiePlot plot = new PiePlot(data);
plot.setInsets(new Insets(0, 5, 5, 5));
//在統計圖片上建連結
plot.setURLGenerator(new StandardPieURLGenerator("link.jsp","section"));
plot.setToolTipGenerator(new StandardPieToolTipGenerator());
JFreeChart chart = new JFreeChart("", JFreeChart.DEFAULT_TITLE_FONT,
plot, true);
chart.setBackgroundPaint(java.awt.Color.white);//設定圖片的背景色
Font font = new Font("黑體",Font.CENTER_BASELINE,20);//設定圖片標題的字型
和大小
TextTitle _title = new TextTitle(title);
_title.setFont(font);
chart.setTitle(_title);
//把產生的圖片放到臨時目錄
ChartRenderingInfo info = new ChartRenderingInfo(new
StandardEntityCollection());
//500是圖片長度，300是圖片高度
filename = ServletUtilities.saveChartAsPNG(chart, 500, 300, info,
session);
ChartUtilities.writeImageMap(pw, filename, info);
pw.flush();
} catch (Exception e) {
System.out.println("Exception - " + e.toString());
e.printStackTrace(System.out);
filename = "public_error_500x300.png";
}
return filename;
}
}
JSP檔案
<%@ page contentType="text/html;charset=GBK"%>
<%@ page import = "java.io.PrintWriter" %>
<%@ page import="net.sentom.chart.WebChart"%>
<%
WebChart chart = new WebChart();
chart.setValue("六月",500);
chart.setValue("七月",580);
chart.setValue("八月",828);
String filename = chart.generatePieChart("www.111cn.net 網站訪問統計表", session, new
PrintWriter(out));
String graphURL = request.getContextPath() + "/servlet/DisplayChart?filename=" + filename;
%>
<HTML>
<HEAD>
<TITLE>www.sentom.net</TITLE>
</HEAD>
<BODY>
<P ALIGN="CENTER">
<img src="<%= graphURL %>" width=500 height=300 border=0 usemap="#<%=
filename %>">
</P>
</BODY>
</HTML> |
